Search found 44 matches

by Martin FERRAND
Fri Sep 07, 2018 9:03 am
Forum: code_saturne usage
Topic: Initializing turbulent flow
Replies: 4
Views: 3761

Re: Initializing turbulent flow

Hello, Concerning the initialisation you can read paragraph 6.3 of the user guide of version 5.0 for instance. Concerning the inlet BC for turbulence, you can either chose established profile with an hydraulic diameter given by the user, or hydraulic diameter and a turbulence intensity. See for inst...
by Martin FERRAND
Fri Sep 07, 2018 7:11 am
Forum: code_saturne usage
Topic: Usage of ALE Module in a duct
Replies: 3
Views: 2346

Re: Usage of ALE Module in a duct

Hello, Is it a valve you want to model? If yes, this boundary should be considered as moving walls. If it is inlet outlet boundary conditions, as mention in the user and the theory guide, isolib BC type retain the flow (imposing a 0 mass flux) when entering (it is a free outlet, but not inlet is all...
by Martin FERRAND
Wed Nov 08, 2017 9:10 am
Forum: code_saturne usage
Topic: cs_user_head_losses.c vs cs_user_source_terms.f90
Replies: 1
Views: 1606

Re: cs_user_head_losses.c vs cs_user_source_terms.f90

Hello Daniele,
That is not normal. What is the version you are using?
Best regards
Martin
by Martin FERRAND
Mon Oct 09, 2017 8:47 am
Forum: code_saturne usage
Topic: Zero gradient at certain faces
Replies: 26
Views: 14815

Re: Zero gradient at certain faces

Dear Odion,

a call function was missing for the vector coupling. I added that to the trunk version. The computation is not crashing anymore but the solvers are not converging properly.

I look at it in the coming days.

Best Regards

Martin
by Martin FERRAND
Mon Sep 25, 2017 7:57 am
Forum: code_saturne usage
Topic: Constant Diffusivity of scalar with drift flux in CS 5.0.4?
Replies: 5
Views: 3014

Re: Constant Diffusivity of scalar with drift flux in CS 5.0

Hello,
You can activate a variable diffusivity and give the same value for all the cells. We have to correct this combination.

Best regards

Martin
by Martin FERRAND
Tue Sep 27, 2016 6:11 am
Forum: Discussion
Topic: How to integrate a new term in equation for scalar ?
Replies: 9
Views: 10271

Re: How to integrate a new term in equation for scalar ?

Hello again,
Just a small additional remark: is "ni" a component of a vector? If so, I would suggest you to move to the trunk version because we add the capability to transport vector species (or if not it will be in the coming days).
Best regards
Martin
by Martin FERRAND
Mon Sep 26, 2016 8:11 pm
Forum: Discussion
Topic: How to integrate a new term in equation for scalar ?
Replies: 9
Views: 10271

Re: How to integrate a new term in equation for scalar ?

Hello Paul, Reading your problem, I think you can do it using DRIFT modelling. Your scalar is nothing else that transported by the velocity u plus a drift (proportional to grad phi). This is possible in version 4.0 to activate drift to a scalar (look at DRIFT in cs_user_parameters.f90) but usually t...
by Martin FERRAND
Fri Aug 19, 2016 6:26 pm
Forum: Discussion
Topic: boundary contribution in cocg_s_it
Replies: 4
Views: 4979

Re: boundary contribution in cocg_s_it

Dear Cédric,

you are right, the new gradient does not need a specifi COCG matrix for cells touching a boundary (because this term is put as explicit, this was done for sake of simplicity for vectors and then extended to scalar to save some time of recomputing it).

Best Regards

Martin
by Martin FERRAND
Sat May 14, 2016 10:44 am
Forum: Discussion
Topic: Oil heat transfer with a low flow speed
Replies: 4
Views: 5897

Re: Oil heat transfer with a low flow speed

Hello,
Your flow is laminar (Re=10^-3), therefore no turbulence models are required.
Best Regards
Martin
by Martin FERRAND
Tue Jan 19, 2016 8:09 pm
Forum: code_saturne usage
Topic: My first study: stratification
Replies: 2
Views: 3481

Re: My first study: stratification

Hello, I will try to answer to some of your interrogations. Concerning the warning about least square gradient, it is not a big deal (the criterion is not universal). What I would suggest for tetras is to use the least square gradient over extended neighbourhood by the way. Concerning the warning ab...